94 E320 Air Pump Issues....What to do?
 

Well, the time has come. The air pump on the E320 is on it's last leg. I unplugged the magnetic clutch two years ago after listening to the horrible noise it makes. Now that noise is back and much worse. The pulley is cocked a few degrees sideways and is going to lock-up, break the belt or fall off in a few days. Now I need a solution ASAP... That's what I get for ignoring the problem.

It's my understanding that only California emissions E320's received an air pump. Is this correct??

Is my only option to replace the pump with a $350 rebuilt unit or can I simply remove the pump and fit a shorter belt? If so, what size belt?

Thanks!
Adam

A new pump is around $1,000, but the dealers sell a rebuild kit for around $200-ish. You remove the air pump, replace the pulley / bearing and reinstall it. My independent did this on my former '93 300E (3.2) "E320", and it worked like a charm.

I was unaware a rebuild kit was available to the public. Thanks for the tip. I will go that route if I can't just pull the pump.
Thanks!
Adam

Rebuilts here seem to run about $200:

http://mbpumps.com/

I have not used them, just found them on the internet. The older gentleman on the phone seemed to know what he was talking about. The pump on my 1991 300CE is still in the whining stage. There were some threads earlier on just changing out the bearing on the pulley but my type is probably like yours with only the clutch up front.


glenmore
1991 300CE
2000 C280
1990 LS400

Since you are not using the pump (clutch disconnected), why not just replace the bearing. I did mine a couple of months ago. Easy. Cost: maybe $20 online. Do a search here and the threads should turn up.

John